Abstract : Fluorine is the most active and the most aggressive chemical element in nature. Until recently destructive properties made impossible use of it for needs of humanity. But now chemists have won victory. Fluorine is mastered and is placed in service of nuclear and jet engineering, aviation and astronautics, science and industry. This book is story of history of mastering of fluorine, full of failures, tragic events and victories, the story of its compounds with inorganic and organic substances and of their truly unusual properties. (Author)